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(The Official amendments to this document would be published by 
the IRC in its periodical, ‘Indian Highways’ which shall be 
considered as effective and as part of the Code/Guidelines/Manual, 
etc. from the date specified therein) 


IRC:122-2017 


GUIDELINES FOR CONSTRUCTION 
OF PRECAST CONCRETE SEGMENTAL 

BOX CULVERTS 





INDIAN ROADS CONGRESS 

2017 


JAIN BOOK DEPOT' 

C - 4, Opp PVR Plaza Connaught Place. 

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Ph 011-23416101 / 02 / 03.09868913553 / 54 / 82 
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IRC:122-2017 


GUIDELINES FOR CONSTRUCTION 
OF PRECAST CONCRETE SEGMENTAL 

BOX CULVERTS 


Published by: 

INDIAN ROADS CONGRESS 

Kama Koti Marg, 

Sector-6, R.K. Puram, 

New Delhi-110 022 

NOVEMBER, 2017 


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IRC:122-2017 


First Published : November, 2017 


(All Rights Reserved. No part of this publication shall be reproduced, 
translated or transmitted in any form or by any means without the 
permission of the Indian Roads Congress) 


Printed by India Offset Press, Delhi - 110 064 
500 Copies 


IRC:122-2017 


CONTENTS 


S.No. 

Description 

Personnel of the Highways Specifications and Standards Committee 

Page No. 

i-ii 

1 . 

Introduction 

1 

2. 

Scope 

3 

3. 

Specifications 

4 

4. 

Construction Methodology 

10 

5. 

Quality Management 

18 

6. 

Precautions and Safety Measures 

20 

7. 

Maintenance 

20 

8. 

Bibliography 

21 


















IRC:122-2017 


PERSONNEL OF THE HIGHWAYS SPECIFICATIONS 
AND STANDARDS COMMITTEE 
(As on 23.06.2017) 


1 

Kumar, Manoj 

Director General (Road Development) & Special Secretary to Govt, of 

(Convenor) 

India, Ministry of Road Transport and Highways, New Delhi 

9 

Singh, B.N. 

Addl. Director General (Incharge), Ministry of Road Transport and 

jL 

(Co-Convenor) 

Highways, New Delhi 

q 

Verma, Dr. S.K. 

Chief Engineer (R) S,R & T, Ministry of Road Transport & Highways, 

o 

(Member Secretary) 

New Delhi 



Members 

4 

Bamezai, Prof. (Dr.) Gita 

R&D, Indian Institute of Mass Communication, New Delhi 

5 

Basar, Toli 

Chief Engineer, PWD, Arunachal Pradesh 

6 

Bhanot, Balraj 

Chairman, TED, Bureau of Indian Standards, New Delhi 

7 

Bongirwar, P.L. 

Secretary (Retd.), PWD Maharashtra 

8 

Gupta, D.P. 

DG(RD) & AS (Retd.), Ministry of Road Transport and Highways, 

New Delhi 

9 

Jain, Prof. (Dr.) S.S. 

Professor, Indian Institute of Technology, Roorkee 

10 

Jain, R.K. 

Chief Engineer (Retd.), PWD Haryana 

11 

Kadiyali, Dr. L.R. 

Chief Executive, L.R. Kadiyali & Associates 
(Expired on 18.02.2016), New Delhi 

12 

Lai, Bhure 

Chairman, Environment Pollution Control Authority, Delhi 

13 

Lai, Chaman 

Engineer-in-Chief, Gurugram Metropolitan Development Authority, 
Haryana 

14 

Narain, Sunita 

DG, Centre for Science and Environment, New Delhi 

15 

Nashikkar, J.T. 

JMD, Maharashtra State Road Development Corporation Ltd., Mumbai 

16 

Pandey, R.K. 

Member (Projects), National Highways Authority of India, New Delhi 

17 

Parida, Prof. (Dr.) M. 

Dean, SRIC, Indian Institute of Technology, Roorkee 

18 

Pateriya, Dr. I.K. 

Director (Tech), National Rural Roads Development Agency, New Delhi 

19 

Pawar, Ajit 

Secretary (Retd.), PWD Maharashtra 

20 

Porwal, Dr. S.S. (VSM) 

ADG (Retd.), Border Roads Organisation, New Delhi 

21 

Raju, Dr. G.V.S. 

Engineer-in-Chief (Retd.), Roads & Building, Andhra Pradesh 

22 

Rawat, M.S. 

Executive Director, AECOM India Pvt. Ltd. 

23 

Sarangi, D. 

CGM, National Highways Authority of India, New Delhi 

24 

Sharma, M.P. 

Chief Engineer, Ministry of Road Transport and Highways, New Delhi 

25 

Sharma, S.C. 

DG(RD) & SS (Retd.), Ministry of Road Transport and Highways, 

New Delhi 


i 











IRC: 122-2017 


26 

27 

28 

29 

30 

31 

32 

33 

34 

35 

36 

37 

38 


1 

2 

3 

4 


1 

2 

3 


Sheokand, Balbir Singh 
Singh, Nirmaljit 
Singh, Pawan Kumar 
Sinha, A.V. 


Executive Engineer, PWD Haryana 

DG(RD) & SS (Retd.), Ministry of Road Transport and Highways, 
New Delhi 

GM, 3M India Ltd. 

DG(RD) & SS (Retd.), Ministry of Road Transport and Highways, 
New Delhi 


Tawade, D.O. Member (T), National Highways Authority of India, New Delhi 


The Director, 
(Chandra, Dr. Satish) 


Central Road Research Institute, New Delhi 


The Director General, 
(Shrivastava, Lt. Gen. S.K.) 


Border Roads Organisation, New Delhi 


The Director General, 
(Mathur, Vishnu) 

The Engineer-in-Chief, 
(Sharma, Lt. Gen. Suresh) 


Society of Indian Automobile Manufactures, New Delhi 


Military Engineer Services, New Delhi 


Tickoo, Bimal Secretary (T), PWD Jammu 

Tiwari, Prof. (Dr.) Geetam Professor, Indian Institute of Technology, New Delhi 


Varshney, Sharad 


Superintending Engineer, Ministry of Road Transport and Highways, 
New Delhi 


Verma, G.L. 


MD, Engg and Planning Consultants Ltd., New Delhi 


Baluja, Dr. Rohit 
Bhowmik, Sunil 

Kandasamy, C 


Corresponding Members 

President, Institute of Road Traffic Education, New Delhi 
Engineer-in-Chief (Retd.), Tripura 

DG(RD) & SS (Retd.), Ministry of Road Transport and Highways, 
New Delhi 


The Director, 

(Patil, Capt. (Dr.) Rajendra B. Central Institute of Road Transport, Pune 
Saner) 


President, 

Indian Roads Congress 

Director General (Road 
Development) & Special 
Secretary to Govt, of India 

Secretary General, 

Indian Roads Congress 


Ex-Officio Members 

(Pradhan, N.K.), Engineer-in-Chief cum Secretary, Works Department, 
Odisha 

(Kumar, Manoj), Ministry of Road Transport and Highways, New Delhi 
Nirmal, Sanjay Kumar 


GUIDELINES FOR CONSTRUCTION OF 
PRECAST CONCRETE SEGEMENTAL BOX CULVERTS 


IRC: 122-2017 


1 INTRODUCTION 

The draft “Guidelines for Construction of Precast Concrete Segmental Box Culverts” was 
first taken up by the Embankment, Ground Improvement and Drainage Committee (H-4) of 
previous tenure i.e. 2012-14. Later, the H-4 Committee was re-constituted for 2015-17 and 
the draft was deliberated in a series of meetings. The H-4 Committee finally approved the 
draft document in its meeting held on 30 th September, 2015 and decided to send the final 
draft to IRC for placing before the HSS Committee. 

The Composition of H-4 Committee is as given below: 


Nashikkar, J.T. 

... Convenor 

Nirmal, Sanjay Kumar 

... Co-Convenor 

Havanagi, Dr. Vasant G. 

... Member-Secretary 

Members 

Adhikari, Atanu 

Khan, Shabana 

Bagli, Shahrokh P. 

Korulla, Minimol 

Chand, Faqir 

Kumar, Anil 

Gajria, Maj. Gen. K.T. 

Raheja, H.S. 

Ghosh, Prof. (Dr.) S.K. 

Ranjan, Gopal 

Gupta, Sanjay 

Rao, P.J. 

Guru Vittal, U.K. 

Seehra, Dr. S.S. 

Jain, N.C. 

Shahu, Prof. (Dr.) J.T. 

Jain, N.S. 

Shaikh, Imran 

Jalota, Dr. A.V. 

Singh, Kuldip 

Katara, U.C. 

Vyas, Saurabh D. 

Kaushik, Shiv 

Das, Atasl 

Corresponding Members 

Madhav, Prof. M.R. 

Sen, Samiran 

Rajagopal, Dr. K. 

Rao, Dr. G. Venkatappa 

Thomas, Dr. Jimmy 

Ex-Officio Members 

President, 

(Pradhan, N.K.), Engineer-in 

Indian Roads Congress 

Chief cum Secretary, Works 
Department, Odisha 

Director General 

(Kumar, Manoj), Ministry of 

(Road Development) & Special 
Secretary to Govt, of India 

Road Transport & Highways 


1 












IRC:122-2017 


Secretary General, Nirmal, Sanjay Kumar 

Indian Roads Congress 

The Highways Specifications & Standards Committee (HSS) considered and approved the 
draft document in its meeting held on 23 rd June, 2017. The Council in its 212 th meeting held at 
Udaipur on 14 th and 15 th July, 2017 considered and authorized Executive Committee of IRC 
to look into matter in consultation with respective Convenors of Technical Committee before 
its publishing. The Executive Committee in its meeting held on 7 th August, 2017 considered 
and approved the same document for printing. 

1.1 Precast concrete segmental box culverts are one of the most versatile and cost 
effective pre-cast concrete products, meeting the needs of fast paced construction projects. 
Flexibility in design and ease of placement at site leads to cost savings. The uses for pre-cast 
concrete segmental box sections are endless. They can be used for underpasses, service 
tunnels, subways, bridges, stream culverts, cattle pass and so on. These guidelines are 
applicable for Precast Concrete Segmental Box Culverts (PCBC) only. A Precast Concrete 
Segmental Box Culvert (PCBC) is an easily installed conduit used to provide passage for 
roads, pathways (or) flowing water (e.g. streams, storm water or drains) underneath roads, 
railways or embankments. Precast concrete segmental box culverts are being used in many 
countries including India. With modern and mechanized box culvert production facilities, one 
can produce over 40 - 60 m length of culvert section per day. 

1.2 Precast concrete box culvert segments are most frequently manufactured and 
delivered captive or commercially as a finished section of required shape. Larger box culverts 
that cannot be transported as a single unit are constructed from two ‘U’ sections for on-site 
assembly. Sometimes two ‘L’ shapes and in between T shapes are also being used. These 
are provided with rebated jointsA/ notched to allow sections to be laid open or sealed. Precast 
Concrete Box culverts may be even provided with precast wing walls and head walls. 

1.3 Other components that may require precast elements include the following: 

1.3.1 Precast Concrete Wing Walls 

Wing Walls are retaining walls placed at the entrance and exit of a box culvert. The walls are 
sloped to match contours of the approaches. Wing walls help to form and protect the ends of 
the box culvert and are designed and manufactured to match precast culvert specifications 
and ground conditions. 

1.3.2 Precast Concrete Head Walls 

Head walls also known as head beams or face walls are typically located between wing walls 
at the end of the box culvert. These walls serve to retain soil above the top slab in order to 
form and protect the culvert entrance and exit. 


2 


IRC:122-2017 


1.3.3 Toe Walls 

A low wall built at the bottom for providing embankment stability and to prevent scour at the 
toe of the embankment. 

1.4 Advantages of Precast Concrete Segmental Box Culvert 

Precast box culverts* have the following main advantages: 

i. The time span of entire construction of conventional culvert: comprising of 
casting base slab, shuttering/de-shuttering and concreting of side walls, slab 
then finishing etc. taking several weeks, gets reduced by use of precast 
element transported and placed to a few days. 

ii. Flexibility of range: can accommodate almost any size requirement: multi¬ 
cell sections of different shapes. 

iii. Ease and rapidity of installation: Can be laid as single or in multiple cells. 

iv. The length of the culvert can be increased by adjoining the units with one 
another. 

v. Eliminates need of transport and erection of shuttering and staging on site 
which leads to reduction in cost and time. 

vi. Being a product made in controlled environment, it exhibits high quality and 
uniformity. 

vii. Aesthetically pleasing: Pre-cast concrete box culverts can also include 
spandrel and wing wall panels with a multitude of architectural finishes. 

viii. In case the design incorporates overfills, there would be no need for approach 
slabs. This not only gives a smooth ride but also reduces maintenance. 

ix. Reduced weather dependency leading to timely completion of the projects. 

x. Superior strength and durability: Strength of pre-cast concrete gradually 
increases over time. 

1.5 The type of precast concrete box section shall be appropriately selected. The 
dimensions of the box section and number of boxes are decided based on the hydraulic 
design as per IRC:SP:13. The box section shall be designed considering super imposed dead 
load, earth cushion, live load including dynamic impact, tractive and braking forces and earth 
pressure as per IRC:6-2017. “Good for Construction” drawings shall be prepared accordingly. 
For longer lengths, multiple segments shall be joined together at site by appropriate method. 


2 SCOPE 

2.1 These guidelines cover the requirements related to Precast Concrete Segmental 

Box Culverts. These guidelines deal with the construction methodologies for single-cell (or) 
multi-cell precast reinforced concrete box sections cast monolithically (or) partly and proposed 
for use in the construction of culverts and for the conveyance of storm water, or plain water. 


3 

















IRC: 122-2017 


These are also used for passage of traffic including usage as road (or) as parking on top of 
these precast reinforced concrete segmental box culverts. 

2.2 The reinforced concrete shall be composed of cementitious materials as per 
IRC:112, IS:456, mineral aggregates as per IS:383, chemical admixture as per IS:9103 and 
water as per IRC:112 all latest editions. For concrete used for precasting of segments, the 
provisions of IRC:112 shall apply. For use of Precast Concrete Segmental Box Culvert as a 
hydraulic structure, the relevant provisions of IRC:SP:13 shall be applicable. Other elements 
like stone apron, wing walls, face wall, toe wall etc. shall also be designed as per IRC:SP:13. 


3 SPECIFICATIONS 

3.1 Many national and international specifications are being practiced and some of 
them are listed out in the Bibliography. 

3.2 The precast concrete box culvert shall be strong, durable and manufactured in a 
controlled environment to ensure accuracy of dimensions and quality of the product. Precast 
production eliminates traditional on-site construction problems caused by substandard 
materials, uncertified craftsmanship, improper curing and bad weather, honeycombing in 
concrete, untimely and improper finish of the components. 

3.3 The concrete mix properties and cover for precast segmental box section (placed 
over a compacted base) shall be selected depending on the severity of exposure condition, 
as specified in IRC:112 and is given in Table 1 or depending upon the concentrations of S0 3 
ions in soil, subsoil or groundwater appropriate protective measures comprising selection of 
type of cement, mix proportions and protective coatings in severe cases as given in Table 2, 
whichever is stringent. 


Table 1 Durability Recommendations for Service Life of at least 100 Years 
(Concrete with 20 mm aggregate) 


Exposure 

Condition 

Maximum Water/ 
Cement Ratio 

Minimum 
Cement Content 
kg/m 3 

Minimum Grade 
of Concrete 

Minimum Cover 
(mm) 

Moderate 

0.45 

340 

M25 

40 

Severe 

0.45 

360 

M30 

45 

Very 

Severe 

0.40 

380 

M40 

50 

Extreme 

0.35 

400 

M45 

75 


Notes: 

(1) All four recommendations given in the Table 1 for a particular exposure condition shall be 
satisfied. 

(2) Minimum cover shown in Table 1 can be reduced by 5 mm in case of factory made precast 


4 


IRC: 122-2017 


concrete elements, high performance concrete, use of stainless steel or controlled permeability 
form work. In case more than one of the above measures are adopted the reduction should 
not exceed 10 mm. 

(3) For elements below ground level, minimum cover shall be 75 mm. 

(4) For design life of 50 years or less, the minimum cover can be reduced by 5 mm. 


Table 2 Requirements for Concrete Exposed to Sulphate Attack 


Class 

Concentration of Sulphates 
as SO, 

Type of 
Cement 

Minimum 

Cement 

Content 

Maximum 

Water 

Cement 

Ratio 

Minimum 
Grade of 
Concrete 

In Soils 

In 

Ground 

Total 

so 3 

% 

S0 3 in 2:1 
water: soil 
extract, g/l 

1 

Traces 

<1.0 

<0.3 

OPC 
PPC or 
PSC 

280 

0.5 

M25 

2 

0.2 to 
0.5 

1.0 to 1.9 

0.3 to 
1.2 

OPC 
PPC or 
SRPC 

330 

310 

0.5 

M25 

3 

0.5 to 
1.0 

1.9 to 3.1 

1.2 to 
2.5 

SRPC 
PPC or 
PSC 

330 

350 

0.5 

0.45 

M25 

M30 

4 

1.0 to 
2.0 

3.1 to 5.0 

2.5 to 
5.0 

SRPC 

370 

0.45 

M35 

5 

>2.0 

>5.0 

>5.0 

SRPC 

With 

protective 

coating 

400 

0.40 

M40 


Notes: 

Type of Cements: OPC: Ordinary Portland Cement Grade 43 conforming to IS:8112 
OPC: Ordinary Portland Cement Grade 53v conforing to IS:12269 
PPC: Portland Pozzolona Cement conforming to IS: 1489 (Part 1) 

PSC: Portland Slag Cement conforing to IS:455 

SRPC: Suphate Resisting Portland Cement conforming to IS: 12330 

3.4 Precast Concrete Segmental Box Culverts may be used in construction applications 
such as conveying storm water, storm drainage, utility conduit, underpasses, service tunnels, 
outfalls and the provision of access. 

3.5 When ordering box culverts to casting yard or a separate manufacturing unit, 
specifications to be followed shall be given in writing and shall include: 

• Specifications for the PCBC 


5 










































IRC: 122-2017 


• Name and location of the project 

• Box size, laying length and the bury depth 

• Design live load 

• Type of joint of two units 

• List of fittings 

• Material test requirements 

• Joint material and quantity 

3.6 Other Requirements 

3.6.1 Site Inspection 

For Precast Concrete segmental Box culvert to work as Cross Drainage (CD) works, 
provisions of IRC:SP:13 shall be followed. For other types of structures the provisions shall 
be as per site specific requirements. 

3.6.2 Designs: Design Discharge, Linear Waterway, Normal Scour Depth, Maximum 
Scour Depth 

i. Hydraulic Design: For box culverts as Cross-Drainage (CD) structure, 
hydraulic design shall be as per IRC:SP:13. 

ii. For box culverts as non-hydraulic structures, the dimensions of the structure 
shall be decided on the basis of site/project requirements. 

3.6.3 Clearances 

For Precast Concrete Box Culverts as CD works, clearances shall be as per IRC:SP:13. For 
concrete box sections as other structures, the vertical clearances shall be as per IRC:54. 

3.6.4 Bed Protection 

For box culverts as CD works, reference may be made to IRC:SP:13. For other structures, 
the precast box shall be placed on plain cement concrete (PCC) of Ml5 bed of adequate 
thickness so as to contain the bearing pressure within safe / allowable bearing capacity of 
the soil below the structure. However, the PCC bed thickness shall not be less than 100 mm. 

3.7 Structural Design 

Structural design of precast concrete segmental box shall be as per IRC:112. Designs shall 
depend on project requirements and applications. The precast concrete segments shall also 
be designed for handling and erection stresses based on the method of construction or 
site conditions. Box culverts can be designed to any standard or custom size and strength, 
including capability for with standing any loads. Additional features can include toe walls, 
headwalls, wing walls, and water tight joints where required and shall be designed as per the 
provisions of IRC:SP:13. The precast concrete segmental box culvert shall be designed for 


6 


IRC:122-2017 


the required forces. The dimensions of top slab, bottom slab and web shall be finalized on 
the basis of designs and project requirements. 

3.8 Foundation 

Box culverts are most suitable, where safe bearing capacity of soil is less than 10t/m 2 . Where 
there are purely clayey strata, the top 900 mm below box should have granular material, like, 
sandy murum or stone dust. Where there is murum and mixed soil having 0 more than 15°, 
there is no need of providing sandy layer. Foundation requirement shall be as per the design, 
loading and site conditions. Segmental Precast Concrete Box cell can also be placed on the 
prepared concrete bed of required strength. 

3.9 The techniques for handling precast units should aim for successful fabrication, 
delivery and installation without causing structural damage, detrimental cracking, architectural 
impairment or permanent distortion. A schematic sketch of a typical Box Cell is given in 
Fig-1- Different uses of a Precast Concrete Box Culvert are shown in Figs. 2, 3 and 4. 



Fig. 1 Typical PCBC with Reinforcement and Haunches at Corners 



Fig. 2 Cattle passing through Box Culvert 


7 









































IRC:122-2017 



Fig. 3 Storm Water passing through Box Culvert 



Fig. 4 Box Culvert as Underpass 


3.10 The aggregates shall be sized, proportioned and mixed with such proportions 
of cementitious materials and water as will produce a thoroughly-mixed concrete of such 
quality that the box will conform to design requirements. All concrete shall have a water - 
cementitious material ratio not exceeding 0.45 by weight. 

3.11 The box sections shall be cured for a sufficient length of time so that the concrete 
will develop a specified compressive strength in 28 days or less. The concrete box shall be 
cured by steam curing or water curing or membrane curing as specified in IRC: 112. 

The base, sub-base and sub-grade shall also be as per the intended usage of box culvert, 
traffic over it and invert level. 

3.12 Precast Concrete Box Segments may be of different sizes and shapes. Figs. 5, 6 
and 7 shows various shapes of segments commonly used in practice. 


8 


IRC: 122-2017 



Fig. 5 Elements of Precast Concrete Segmental Square Box Culvert 



Fig. 6 Elements of Precast Concrete Segmental Rectangular Box Culvert 



Fig. 7 Elements of Precast Concrete Segmental ‘C’ Section Box Culvert 


9 




































IRC: 122-2017 


3.13 Culverts shall be subject to loading as per design. The lifting system for precast 
concrete box culverts shall be simple, based on available resources, consistent with the 
design and without compromising quality (Figs. 8 and 9). 



Fig. 8 Fig. 9 

Figs. 8 & 9 Lifting System of Elements of Precast Concrete Segmental Culvert 


4 CONSTRUCTION METHODOLOGY 

4.1 Types of Manufacturing Methods 

There are two main methods of casting of PCBC. These are 

i) Dry cast (Machine Made) 

ii) Wet Cast 

4.2 Dry Cast Method 

In this method precast segments are cast using mechanized equipment. Form vibrators 
consolidate zero-slump concrete between core and jacket. Hole formers can be incorporated, 
or sometimes coring is resorted to as may be needed. The Precast Concrete segment is 
immediately stripped and the form is reused. Segments are typically cured in a curing tank, 
or moisture curing is used. 

4.3 Wet Cast Method 

In this method, the precast concrete segments are typically cast on using an inner and outer 
form. Forms shall be cleaned of concrete build-up after each use.Block outs/hole formers can 
easily be incorporated before concreting. The segments are cast using conventional concrete 
or self-consolidating concrete. Concrete cover shall not be less than that given in Table 1. 
Precautions shall be taken to ensure that the reinforcement does not move significantly 
during the casting operations. The segments are cured in the form. 


10 


IRC: 122-2017 


IS:15916:2010 gives various accepted methods of manufacture of precast units. These have 
been broadly classified as: 

a) The ‘Stand Method’ where the moulds remain stationary at places, when 
the various processes involved are carried out in a cyclic order at the same 
place, and 

b) The ‘Flow Method’ where the precast unit under consideration is in movement 
according to the various processes involved in the work which are carried out 
in an assembly-line method. 

Any method which is suitable to the project and site requirements shall be adopted. 

4.4 Curing methods 

Moist/wet curing, steam curing or Membrane curing shall be adopted as per IRC:112 

4.5 Identification and Marking 

All precast units shall bear an indelible identification, location and orientation marks as and 
where necessary. The date of manufacture shall also be marked on the segments. The 
identification markings on the drawings shall be shown in a table on the setting schedule 
together with the length, type, size of the unit and the sizes and arrangement of all reinforcement 
for easy identification of the segment. 

4.6 Dimensions of the precast segmental box unit shall conform to the design 
requirements. The transportation/shifting of the pre-cast elements shall be carried out only 
after achievement of minimum strength of 20 MPa or 0.7 times the compressive strength of 
concrete. The strength of concrete shall be tested as per IS:516. 

4.7 The delivery and off loading of precast concrete box culverts segments should be 
well planned. A suitable hard access that can be used safely by standard delivery vehicles 
and a suitable crane of adequate capacity shall be provided in the casting yard. The pre-cast 
concrete segments shall be properly cured to ensure achievement of appropriate strength. 

4.8 Handling 

Products shall be stored, handled shipped and unloaded in a manner to minimize damage. 
The handling process encompasses the demoulding of the precast units, their loading and 
transportation to storage areas, offloading and storage, transfer to site and site erection. 
To avoid excessive stresses and possible damage, all precast units should be handled in 
the manner as envisaged in their design by means of approved devices, identified in the 
production and erection drawings. 

4.9 Lifting Equipment, Accessories, Storage, Transportation and Installation 

Lifting holes or inserts shall be consistent with industry standards. Lifting shall be 
accomplished with methods or devices intended for this purpose Lifting equipment such as 
mobile crane, gantry crane, forklift etc. must be carefully selected to ensure that lifting of 


11 














IRC:122-2017 


precast units is carried out within the rated capacity of the equipment. The support for the 
lifting equipment must be checked to ensure that adequate supporting capacity is provided. 
Lifting accessories may comprise combinations of lifting beams or frames, slings or cables, 
hooks or shackles. The selection of each of these components should be predetermined to 
take account of the forces exerted on them due to various aspects of the lifting operations. A 
person suitably qualified in accordance with the relevant regulations must regularly inspect 
all lifting equipment prior to and after use. Results of such inspections must be properly 
recorded and be available for subsequent inspection. The location of lifting points should be 
clearly indicated on the drawings. Lifting methods may differ from different manufacturers 
and the same shall be agreed upon. Verticality or otherwise of the lifting ropes shall be as per 
the design requirements. During operation of lifting and unloading the precast concrete box 
culvert segment shall be protected from damage particularly the joining surfaces. Also, due 
care shall be taken for safety of the crew during this operation. 

4.9.1 Factory/Casting Yard and Site Storage 

Storage areas must be large enough so that the precast units can be stored safely, with 
adequate room for lifting equipment and transporting vehicles to manoeuvre. The ground of 
the storage area must be hard, level, clean and well drained to permit organised storage. 
Precast segments can be damaged by incorrect stacking and storage. Where the locations 
of support points for a precast unit are critical, the locations for the supports should be noted 
on the shop drawings. 

Supports must be arranged to avoid twisting or distorting of the precast segments and must 
be adequate to transfer the weight of the stacked units to the ground without excessive 
settlement. 

The stored and stacked units should be protected to prevent accidental damage and 
discolouration and the support material should be non-staining. Lifting points should also be 
well protected and kept accessible while the units are in storage. Precast segments must be 
stored safely with adequate supports such that it would not endanger any workers moving in 
the vicinity. 

4.9.2 Transportation 

Commonly precasting yards are at a distance from the project site where in these segments are 
to be used. Hence, it is necessary to transport them from casting yard to the construction site. 

Transportation requirements will need to be met and permits, where applicable, obtained. 
Transportation must comply with the appropriate regulations. The precast units should have 
gained sufficient strength before being loaded for transportation. 

4.9.3 Loading and Storage on Transporters 

Precast units must be loaded carefully on to delivery vehicles to prevent damage. To protect 
the edges throughout their journey, proper devices should be used to support, secure and 
wedge the precast units. The units should be adequately secured and supported to prevent 
them from overturning, shifting or being damaged during transportation. Adequate non¬ 


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staining cushioning should be provided between the unit and any securing chains, cables or 
ropes to prevent localised damage. 


Precautions should also be taken to ensure that no undesirable stresses will be transmitted 
to the precast unit due to any flexing of truck or trailer. Typical transportation vehicle is shown 

in Figs. 10,11 and 12. 



Fig. 10 Transportation of Sections of Box Culvert 



Fig. 11 Transportation of Sections of Box Culvert 



Fig 12 Transportation of Sections of Box Culvert 


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4.9.4 Erection Preparation 

Consideration should be given to the following items to ensure safe and efficient installation of 
the precast elements in accordance with the design intent. For designing erection of precast 
concrete segments, provisions of Sub clause 11.10 of IS: 15916:2010 shall apply. 

Propping and temporary support details 

If the sequence of erection is critical to the structural stability of the structure, or for access to 
connections at certain locations, it should be noted on the drawings. The erection drawings, 
which should include all relevant information, should be prepared prior to the commencement 
of any erection during Erection Safety. 

Safety during the handling and erection of precast concrete elements is of paramount 
importance and compliance with the relevant current regulations is required. 

All equipment used for the handling and erection of a precast element must be maintained to 
a high standard, load tested as necessary, and be suited to the intended use. Consideration 
should also be given to the site environment particularly with regard to built up areas and 
implications this may have on erection safety. 

Erection sequence 

Precast segments should be erected in accordance with a pre-planned sequence as detailed 
in the erection drawings. This sequence of erection should be such that the multiple handling 
of elements is minimised. A trial erection operation should be considered to identify any 
unforeseen erection difficulties. 

4.9.5 Missing or Damaged Lifting Inserts 

If missing, faulty or incorrectly located lifting inserts are identified, the designer should be 
contacted immediately to assess the problem and decide on an alternative lifting system. 
It should be verified, where permanent fixings or connections are temporarily used during 
construction, that the fixings are suitable for the temporary use and their long-term performance 
will not be compromised. 



Fig. 13 Lifting and Placing of Box Segment 


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Erection tolerances 

Generally, the precast unit should be erected in accordance with the stipulated tolerances, 
used in the design and specifications. Fig.13 shows some lifting and placing of Box Segments 

4.9.6 Bedding Details 

m 

Bedding details for box segments shall be as designed and specified. Proper support for a 
box culvert consists of specified bedding material having uniform flat surface as low or high 
points could create stress concentrations in the box after installation. The box segment, 
once installed, will not normally settle; it cannot be forced down to grade. Coarse bedding 
materials are not beneficial due to their irregular shape and sharp angles; instead medium 
to fine granular material should be used if concrete bedding is not used. A bedding thickness 
shall not be less than 100 mm. The width of the bedding material should equal the width of 
the box (span plus twice the wall thickness) and the length of the bedding material should 
equal the length of the box. In the event that the levelling course consists of layers with the 
upper layer being clean, uncompacted sand, that layer shall be a maximum thickness of 50 
mm to prevent non-uniform settlement from personnel and equipment during the installation 
process. If rock strata or boulders are encountered under the box section, the same shall 
be removed and replaced with additional levelling course material. A concrete slab is not 
considered as an appropriate leveling course. 

The box will tend to pull some bedding material toward the connection as it is aligned with 
the previous box segment. Excess bedding material trapped in the joint will prevent a proper 
alignment and connection and hence should be prevented. Therefore, at the connection 
end, a small trench should be dug. This allows for the bedding material to fall into the trench 
instead of the joint when the box is pulled into place. All bedding material characteristics 
should correspond to code and designer’s plans for the specific project. Correct installation 
requires that the box culvert be installed on properly graded bedding. Any discrepancies 
in the installation of the culvert regarding bedding or grade should be addressed with the 
designer for remedial action. Bedding below box is shown in Fig. 14. 



Fig. 14 Bedding Below Precast Concrete Segmental Box Cell 


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4.9.7 Box Alignment during Installation 

It is critical that the first box segment should be installed correctly as it will determine the line 

and grade of the following boxes/segments. If these are not correct, future connections may 

be affected. The trench/bed shall be checked for line and gradient. 

4.9.8 Box Placement 

A box culvert line shall be usually laid from downstream end and a suitable joint sealing 
arrangement should be made. Placement of boxes should start at the outlet end of the line 
of box sections. The bell end should point upstream and the spigot or tongue should point 
downstream. Unless otherwise approved by the owner, loads from construction equipment 
transferred to a box section before, during, or after fill placement, either directly or through the 
fill, should not be greater than the loads assumed in the design. Using excavating machinery 
for the purpose of pushing boxes into place should be avoided, since this could cause 
cracking, requiring on-site repairing. Also, dropping or dragging the section over gravel or 
rock shall be avoided. A proper foundation for construction equipment should be available on 
site in order to ensure that no damage is caused to the levelling course and the sidewalls of 
the excavation area. PCBC shall be placed properly on the constructed base. The base shall 
be firm to avoid settlement of the units after loading. Bedding shall be properly designed. 
Improper bedding could prevent the tongue of the box from being properly inserted into the 
groove. It is very important that time be spent to ensure the box culvert bedding preparation 
is done correctly. Placement of Box Segment is shown in Fig. 15 



Fig. 15 Placing of Section of Box Culvert 


4.9.9 Joints Sealing 

Many methods for jointing and sealing are available. The joints and sealing of units shall be 
as per the design or project requirements. The design of joints shall be made in the light of 
their assessment with respect to feasibility, practicability, serviceability considerations as per 
IS: 15916:2010. 


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4.9.10 Normal joint is socket and spigot joint and same is generally used in culvert 
construction. Jointing is important in reducing the migration of soil fines and water between 
box sections and their surroundings. Depending on the use of the box culvert, various 
materials and methods may be used for sealing the joints. Box culverts specified for a soil- 
tight joint can be sealed between the joint with a bituminous mastic sealant. Either liquid butyl 
(bulk mastic) or non-shrink grout can be added to the outside top slab and applied down the 
sidewall 300 mm as well as applied to the inside bottom slab and inside sidewalls; or butyl 
sealant 25 mm thick and placed on the inside bottom and halfway up the sides of the bell end 
(approximately 13 mm from edge) and placed on the outside top and halfway down the sides 
of the spigot end (approximately 13 mm) from edge can be used to seal a soil tight joint. In 
cold weather it may be necessary to heat the butyl sealant with a hot water bath, bottle gas 
torch, or both. Placing this joint material in a sunny location, just prior to use, will allow heat 
absorption and make it more workable. Different grades of joint material are available for 
different temperatures. 

Another joint commonly used is an extruded sealant which is placed between the joints. The 
extruded sealant can be applied in the same manner as the bituminous sealant, applied to 
the bell and spigot end of the sections being joined. In some areas, rubber gasket box joints 
may be available. Pre-made foam gaskets can also be used to seal joints. However these 
forms of sealant will have to be manually attached to the bottom of the spigot end of the box 
to prevent sagging. If the seal is insufficient then an added layer of adhesive joint wrap (butyl 
rubber laminated to polyethylene vapour retarder) can be used on the outside of the box to 
prevent infiltration. The external sealing band can also be non-woven geo-textile and should 
be placed on the sides and top of the box after installation. In certain situations, all four sides 
can be wrapped. In this case, the geo-textile material can be slipped under the box before it 
is set, then the sides and top can be sealed after the box is in place. 

4.9.11 Backfilling should commence as soon as possible after the Precast Concrete 
Segmental box culverts have been placed by filling the trench evenly on both sides with a 
drainage layer of min 600 mm thickness and rest by using approved materials in layers not 
exceeding 200 mm. Backfill should be placed in uniform layers along the sides of the boxes 
and over the top of the box sections wherever required. The backfill material should not 
contain debris, organic matter, or large stones with a diameter greater than 1/2 the thickness 
of the compacted layers being placed. When vibratory compactors are used to compact the 
backfill material, care should be taken to avoid damage to the Box cell. In sections in cutting 
where space is a constraint, the back filling shall be done with granular material like coarse 
sand/gavel. Lift holes shall be properly sealed and plugged. 

4.9.12 Construction machinery shall not be used over the box culvert without proper 
protection. Care must be taken since site traffic and construction equipment over shallow 
fill depths can impose loadings greater than those for which the finished box culvert has 
been designed. If construction equipment is going to travel over installed box sections, a 
temporary compacted backfill should be placed to a minimum of 1 m over the top of the box 
section unless the box has been specifically designed for the anticipated construction loads. 
The loads applied to the box section should not exceed those specified by the designer. In 


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an embankment installation, the minimum amount of backfill should extend one box section 
span or 1 m, whichever is larger, in each direction to prevent lateral displacement. 

4.9.13 Box cell structures are to be provided with curtain walls and apron and these must 
be completed before floods. The best practice is to lay foundations of curtain wall and apron 
first and then lay the box. Apron pitching, toe walls etc shall be designed as per provisions of 
IRC:SP:13. 

4.9.14 Made up of separate segments that are assembled in the field to make the final 
structure, segmental box sections are being used in building culverts for underground 
conveyance of storm water. In addition, culverts can also function as pedestrian tunnels as 
well as wildlife passage areas under heavily travelled highways. 

4.9.15 Equipment used- Equipment used for precast concrete segments shall satisfy the 
requirements stipulated in IS:15916:2010 


5 QUALITY MANAGEMENT 


Quality Control 

Fabrication precast segmental box culverts is simple and is generally done in the fabrication 
yard or casting unit. It is necessary to have quality control system in place for all elements, 
material and ingredients used in fabrication. Reference may be made to “Guidelines on Quality 
Systems for Road Bridges”, IRC:SP:47-1998. The specifications shall be in accordance with 
“Specifications for Road and Bridge Works” of Ministry of Road Transport and Highways 
published by the Indian Roads Congress. 

5.1 Factory 

For a mass scale production, the factory for the casting of units must ensure that the precast 
units are manufactured under a Quality Management System certified under ISO 9000 
covering the following items: 

• quality control tests of materials; 

• calibration of laboratory equipment for quality control tests; and 

• production process and control of equipment at the casting yard. 

The factory and contractor shall be responsible for maintaining the quality of the manufacturing 
process for the precast units. The authorised person/registered structural engineer must 
satisfy himself that the precast concrete units have been constructed in accordance with 
the approved drawings and specifications. This may be achieved by providing full time 
construction supervision by their representative. If more stringent control on quality is 
considered necessary, the authorized person/structural engineer may step up the supervisory 
and testing requirements at appropriate place to test check the quality of the material and 
finished product. 


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Rigorous quality control procedures must be maintained at the precasting factory/casting 
yard at all times to ensure that the precast segments are constructed in accordance with the 
designs and specifications. 

Upon leaving the precasting factory/casting yard all precast segments or batch of segments 
must carry documentation certified by the factory/casting yard stating that the segments have 
been manufactured under a certified quality assurance scheme and in accordance with the 
prescribed specificatiens. 

5.2 Testing Standards 
Concrete 

Sampling and testing of concrete should comply with the IS: 1159 and IS: 516 and as required 
by the contract documents. The testing is to be undertaken by equivalent approved accredited 
laboratory. 

Reinforcement 

Reinforcing steel shall be of HYSD steel as per Table 18.1 of IRC:112. For seismic zones 
III, IV and V, HYSD bars having minimum elongation of 14.5% and conforming to other 
requirements of IS:1786 shall be used. 

According to IRC: 112, the corrosion resistance of reinforcing steel can be improved by 
using (i) galvanised reinforcement with coating as per IS: 12594-1988, (ii) Epoxy coated 
reinforcement conforming to IS: 13620-1993 or by (iii) stainless steel reinforcement conforming 
to IS:6744:2001 

Sampling and testing of reinforcement should comply with the IS code. All testing is to be 
undertaken by equivalent approved accredited laboratory and in accordance with IS code or 
contract specifications 

5.3 Site 

The receiving, lifting, storage and erection at the construction site should be undertaken in 
accordance with the site accredited quality assurance scheme. The following items should 
form part of the site checking for acceptance of the precast elements: 

Structural integrity 

Although quality control checks are carried out for the precast units at the factory, there is a 
possibility of damage during handling and transportation. As the precast units are received 
on site they should be visually inspected for any signs of structural defect. Acceptance of 
any structural defect should be assessed with regard to the causes and the overall structural 
integrity of the precast units. 

Dimensional tolerance 

Dimensional tolerances of the precast units as received on site should comply with those 
specified in the contract documents. Changes to the dimensions and shapes of units should 


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IRC: 122-2017 


be identified and assessed with regard to the overall tolerance; and surface finish. Finished 
segment tolerances should not exceed the following: 


Length of segment (not cumulative): ± 5 mm 

Overall span length : ±10 mm 

Web thickness, depths of top and bottom flanges, 

Width of top and bottom flanges, overall depth 

of segment, thickness of diaphragm: ± 5 mm 

Grade of form edge and soffit: ±1.0 mm/m 

The surface finishes of precast units when received on site should be checked for compliance 
with the requirements of the contract documents. 


6 PRECAUTIONS AND SAFETY MEASURES 

(i) Precast concrete segmental box shall be designed duly considering the 
loads, forces, handling, lifting, transport arrangement on site etc. 

(ii) The lifting of the precast segment from the casting yard shall not commence 
unless the strength of the concrete achieved is checked and confirmed as 
per design. 

(iii) Lifting arrangement, ropes, anchors for segment shall be designed for weight 
of segment, possible jerks, possible overloading etc. 

(iv) During lifting and erection of the precast segment, workmen shall keep away 
at safe distance from the hanging segment to avoid any accident. 

(v) Care shall be taken while handling or placing the precast segment to protect 
the edges, corners, shear keys etc. 

(vi) Pulling of precast segments on the bed shall be avoided. 

(vii) Uniform curing of the entire precast segment in the casting yard shall be 
ensured. 

(viii) Design and preparation of the bed supporting the Precast Segment shall 
be done well in advance duly considering loads, forces to be sustained and 
bearing capacity of the strata below. 

(ix) Construction machinery shall not be permitted on the top of the segment 
unless requisite earth cushion of 1.0 m is proved and loads are considered 
in the designs. 

(x) Precast concrete segment shall be carefully inspected and checked for any 
cracks, spalling etc after casting as well as on placement on site. 

7 MAINTENANCE 

Precast box culvert requires little maintenance. However, routine pre and post-monsoon 
inspections need to be carried out to check the condition of bedding, apron and other silt 
deposition, scour, etc. Large box sections can be entered and examined. Timely action needs 


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to be taken to rectify/repair the defects noticed. Some of the typical defects and remedial 
actions are as given below: 

• Debris shall be removed. 

• Excessive cracks or large cracks noticed shall be repaired. 

• Joints are properly sealed. 

• The Invert shall be smooth and free of sags or high points. 

• Lift holes are properly filled. 

• Hook-ups, diversions and connections are properly made. 

• Catch basins and inlets are properly connected. 

• Manhole frames and covers are properly installed. 

• Surface restoration and all other items pertinent to the construction are 
properly completed. 


8 BIBLIOGRAPHY 

1. IS:456:2000 Code of Practice for Plain and Reinforced Concrete, BIS, New Delhi. 

2. IS: 1199:1959 Methods of Sampling and Analysis of Concrete, BIS, New Delhi. 

3. IS:383:2016 Specifications for Coarse and Fine Aggregates from Natural Sources 
for Concrete, BIS, New Delhi. 

4. 1S:516:1959 Method of Test for Strength of Concrete, BIS, New Delhi. 

5. IS:9103:1999 Concrete Admixtures-Specification (First Revision), BIS, New Delhi. 

6. IRC:SP:13-2004 “Guidelines for the Design of Small Bridges and Culverts”, IRC, 
New Delhi. 

7. IRC:6-2017 “Code of Practice for Road Bridges, Section-ll Loads and Load 
Combination”, IRC, New Delhi. 

8. IRC:78-2014 “Code of Practice for Road Bridges, Section-VII Foundation & 
Substructure”, IRC, New Delhi. 

9. IRC: 112-2011 “Code of Practice for Concrete Road Bridges”, IRC, New Delhi. 

10. Ministry of Road Transport and Highways (2013), Specifications for Road and 
Bridge Works, IRC, New Delhi. 

11. ASTM C 1433-16b, Standard Specifications for Precast Reinforced Concrete 
Monolithic Box Sections for Culverts, Storm Drains, and Sewers, ASTM 
International, Unites States. 

12. B.N. Sinha and R.P Sharma (2009), “RCC Box Culvert - Methodology and Designs 
Including Computer Method”, Paper No : 555, Journal of the Indian Roads 
Congress, October-December, p 189. 

13. Concrete Pipe and Box Culvert Installation Guide, American Concrete Pipe 
Association. 

14. IRC:54-1974 “Lateral and Vertical Clearances at Underpasses for Vehicular 
Traffic”, IRC, New Delhi. 


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